The present invention relates to poultry processing and more particularly to a method and apparatus for processing the gizzards of poultry such as turkeys.
In modern poultry processing plants, hundreds of thousands of birds may be handled on a daily basis. To meet these production rates, the processing plants have become highly automated. Various operations are conducted on the birds as they travel through the plant hanging from overhead conveyors. Typically, important internal organs of the poultry, such as gizzards, will be processed separately by hand or on special machines. During such processing, the gizzards are separated from the stomach and entrails. This operation may be conducted by hand or by suitable machinery as the poultry passes on an overhead conveyor. The gizzards must then be cleaned to remove stones, sand and gravel from the interior of the gizzard. Next, the tough, inedible, interior liner of the gizzard must be removed.
During the processing operation, a rotary knife may be employed to cut open the gizzard. Available cutters split the gizzard randomly or through the meaty part of the lobe. A desirable butterfly cut through a tendon leaving the meat intact is not obtained. Further, unless the gizzard interior is clean with the small stones, sand and gravel removed prior to the cutting operation, the rotary knife will become rapidly worn. As a result, various methods have been proposed which direct jets of pressurized water into the interior of the gizzard prior to the cutting operation. Examples of prior gizzard apparatus and processing methods may be found in U.S. Pat. No. 3,590,421 entitled "MACHINE AND METHOD FOR CLEANING AND CUTTING OPEN GIZZARDS OF SLAUGHTERED BIRDS" and issued on July 6, 1971, to Leth et al; U.S. Pat. No. 3,579,714 entitled "GIZZARD PROCESSING DEVICE" and issued on May 25, 1971, to Edwards, Sr.; U.S. Pat. No. 3,175,244 entitled "METHOD OF PROCESSING GIZZARDS IN FOWLS" and issued on Mar. 30, 1965, to Sharp et al; U.S. Pat. No. 3,624,669 entitled "POULTRY GIZZARD PROCESSING MACHINE" and issued on Nov. 30, 1971, in the name of Lewis; and U.S. Pat. No. 4,538,325 entitled .music-flat.GIZZARD HARVESTING MACHINE" and issued on Sept. 3, 1985, in the name of Harben et al.
Another approach uses a pair of opposed conveyors which define cooperating pockets for receiving and holding a gizzard. The conveyor moves the gizzard onto a rotating cone spindle. The spindle washes foreign matter from the gizzard and removes its lining by rotating the lining with respect to the gizzard. The spindle defines washing ports or nozzles at its tip. The gizzard is then passed on for further processing, such as defatting and packaging.
In the processing of poultry gizzards, such as those from turkeys, various problems have been encountered. These include mutilation, insufficient cleaning and reduced production rates. It is desirable to automate the processing operation yet avoid damage to the gizzards as they are cleaned and delined. Prior automated equipment have had excessive wear problems, excessive mutilation problems and excessive maintenance and cleaning problems.